Ground Penetrating Radar

Date 18 August 2012 - 22 August 2012

Event ID 992745

Category Recording

Type Ground Penetrating Radar

Permalink http://canmore.org.uk/event/992745

NR 39689 62507 – NR 39954 62496 – NR 39729 62955 and NR 40014 62996 (township and enclosure) and NR 40035 63045 (mound) A third season of the survey of the remains of the 19th-century township of Airigh Ghuaidhre and surrounding prehistoric remains took place 18–22 August 2012.

The focus in 2012 was a ground penetrating radar survey of a possible burial mound at NR 40035 63045, which showed promise following the resistivity survey in 2011 (DES 2011, 44–45). Noggin Plus system was used with 500MHz antennas mounted on a SmartCart. A grid measuring 30 x 30m was surveyed over the mound with 0.5m traverse spacing and the directions of traverse perpendicular to the mound, i.e. ESE–WNW, in zig-zag mode. Additionally, seven longitudinal profiles were collected along NNE–SSW orientation. The GPR survey was successful in obtaining information from a depth exceeding the capabilities of the resistivity survey. The results showed strong reflections, equivalent to the high resistance anomalies suggestive of a possible cairn structure, but continuing much deeper than previously known and suggesting that the core of the mound could be grassed-over bedrock. A 2 x 1m trench was excavated at the SW edge of the mound to test the geophysical results. The mound proved to be natural in origin and composed of steeply rising limestone bedrock, which gave the mound such striking edge definition in the resistivity results.

Seven GPR lines at 3m intervals were collected in the S–N direction over the chapel enclosure, which was previously surveyed with the resistivity survey (DES 2010, 41). The purpose of the GPR survey was to investigate the possible presence of graves in the enclosure and obtain a lateral profile of the proposed chapel structure situated at the E end of the enclosure. In addition, two 2D lines measuring 65m and 74m were collected at the site of possible hilltop enclosure (DES 2011, 44–45). The lines were positioned across the southern extent of the possible enclosure to investigate the profiles of putative ditches and locate their eastern return. This data is currently being processed.

Archive: University of Southampton

Funder: University of Southampton and University of Reading

Darko Maricevic, University of Reading

Steven Mithen,

Karen Wicks,

2012